The personal, societal, and economic burden that disorders of the central nervous system (CNS) place on the United States is tremendous. For mental health care alone, direct costs were estimated at $57.5 billion annually. This is in part due to failures in developing effective medications. From 2003-2014, the FDA approved just 37 new drugs to treat CNS disorders covering the clinical areas of neurology, psychiatry, and pain. That averages to just three new chemical entities (NEIs) per year, while clinical trial failure rats for CNS drug development remain greater than 90%. Although the reasons for this exceedingly high level of attrition are myriad and complex, the central challenge to drug development is that platforms for early preclinical identification and validation of novel compounds are often not relevant to the target disease. BrainXell, Inc. seeks to address these issues head-on by generating in vitro model systems that more closely approximate the human CNS. This SBIR Phase I proposal is to produce large quantities of highly enriched, functionally specialized neurons of consistent quality that meet high-throughput screening (HTS) requirements. We have selected cortical glutamatergic neurons as the neuron subtype for this project. These neurons are affected in a large number of psychiatric diseases, including depression and schizophrenia. We have engineered a human iPSC line with constitutive expression of nanoluciferase, allowing us to evaluate combinations of small molecules designed to rapidly expand cortical neural progenitors. This goal will be achieved by modifying approaches used previously to generate large numbers of highly pure motor neurons. We will also identify and develop novel dissociation solutions and freezing media to promote survival following disaggregation and thawing, thus reducing costs and making it practical for HTS. Formulation of an effective cocktail for expanding and maintaining cortical progenitors will not only enable us to manufacture cortical glutamatergic neurons for HTS from normal as well as patient iPSCs, but also provide the technical basis to accomplish the same goal with other neuronal subtypes, such as cortical GABAergic neurons or midbrain dopaminergic neurons.